Over at the Status Report blog, researcher “Volketten” has created a post about an ill conceived plan to convert a grab crane into a gun carrier in the UK in 1940.

Excerpt:

In 1940 Britain was fighting for its life and a multitude of good and not so good ideas were put forward to develop new armored vehicles to meet the needs of home defense and the British Army overseas. Lincolnshire was a hub of development at the time from a variety of companies and one of them was the firm of Ruston-Bucyrus. Founded in 1930 the firm was a merger of the Lincolnshire firm of Ruston and Hornby (who had already had some experience with track laying vehicles in WW1 during the development of early British tanks) and the American firm of Bucyrus-Erie of Bucyrus, Ohio.

They specialized in vehicles for earth-moving and excavation mainly track based although there were a couple of walking machines. By 1940 they were already placed under contract to build some British Cruiser tanks but they also tried to develop their own expertise in cranes for a more military use and the vehicle chosen to prototype the design was an old rusting RB-10 grab crane.